Most of my machines have a coin slot incorporated in them to get them working; just like a real arcade game. There's a number of reasons for this.

 

Firstly, it's what you would expect on an arcade game. These are rarely free to use and having a paid entrance at least means the owner/maker is getting a return for the investment in the machine. It is a crude, but effective means of measuring appreciation.

 

Secondly, that accords with my own attitude. Although the coin slots don't actually do anything with these machines they are a reminder that there is a transaction between the viewer/user and the maker. If you did have to drop a coin in, you would probably give it your attention for the operating period, rather than the 10-15 seconds most artworks get in a gallery.

 

Practically, research has shown that nowadays it is unlikely that a viewer will have coins in their pocket and it's also attractive for thieves. To get around this were the machines actually needing coins they would more likely be triggered with tokens, tokens that could be purchased somewhere beforehand. Triggering by text message was investigated and approved by Ofcom (!), but the cost per play would be high at approximately £6.

 

For help and guidance, I am indebted to Tim Hunkin and 'Under the pier' website.

These pages in particular were of assistance: https://www.underthepier.com/01_howtocoinmech.htm and https://www.underthepier.com/13_in_praise.htm